000
AXPZ20 KNHC 090036 RRA
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN JUL 8 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...TROPICAL WAVES...
TROPICAL WAVE N OF 4N ALONG 83W MOVING W 15 KT. CONVECTION 
ASSOCIATED WITH THIS WAVE IS LINKED TO THE ITCZ AND THE PACIFIC 
COAST OF COSTA RICA.

TROPICAL WAVE EXTENDING SW-NE FROM 7N117W TO 18N114W WITH WEAK 
LOW PRES NEAR 14N116W MOVING W 10-15 KT. THIS WAVE CONTINUES TO 
PART OF A BROAD AREA OF LOW PRES THAT EXTENDS ROUGHLY FROM 
10N-17N BETWEEN 115W-121W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION BEING GENERATED BY COMBINATION OF CONVERGENCE INTO 
THE LOW NEAR THE SURFACE AND FAVORABLE OUTFLOW ALOFT.

...ITCZ...
AXIS IS CENTERED ALONG 10N85W 9N95W 15N115W 9N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM S OF AXIS E OF 
105W. SCATTERED MODERATE ISOLATED STRONG CONVECTION FROM 9N TO 
19N BETWEEN 110W AND 124W. SCATTERED MODERATE CONVECTION FROM 6N 
TO 9N W OF 136W.

...DISCUSSION...
THE WEAK SURFACE LOW NEAR 14N116W IS THE PRIMARY FEATURE TODAY. 
OVER THE PAST DAY ITS BROAD CIRCULATION HAS FAILED TO ORGANIZE 
AND CONSOLIDATE...LEAVING ONLY AN ELONGATED TROUGH WITH MULTIPLE 
LOW LEVEL CENTERS. THE PRIMARY CENTER APPEARS FURTHER N NEAR 15N.
A BROAD UPPER RIDGE ALLOWING GOOD OUTFLOW OVER THE SURFACE TROUGH
WILL KEEP CONVECTION FIRING AS THE TROPICAL WAVE ASSOCIATED WITH
THIS LOW MOVES WEST. ANOTHER WEAK SURFACE LOW NEAR 8N137W HAD A 
BRIEF FLAREUP IN CONVECTION EARLIER TODAY...BUT HAS DISSIPATED. 
GLOBAL MODELS DO NOT FAVOR DEVELOPMENT OF EITHER LOW. ALTHOUGH 
CONVECTION HAS DECREASED OVER THE PAST 6 HOURS...THE ITCZ IS 
FAIRLY ACTIVE EAST OF 110W. QUIKSCAT SHOWS ENHANCED SOUTHERLY 
CROSS-EQUATORIAL FLOW INTO THE TROUGH...RESULTING IN INCREASED 
SHOWER ACTIVITY ALL ALONG THE EASTERN PART OF THE ITCZ. THE MOST
STRIKING FEATURE INDICATED BY THE MODEL GUIDANCE OVER THE NEXT 
36-60 HOURS IS A SURFACE LOW OFF THE CENTRAL CALIFORNIA COAST 
WHICH RETROGRADES TO A POSITION NEAR 36-37N 127W-128W TUESDAY 
EVENING. THE NET EFFECT S OF 30N WILL BE A DISRUPTION IN THE 
NORMAL TRADE WIND PATTERN IN THE NW PART OF THE DISCUSSION AREA 
WHICH REDUCES THE NE TRADES TO AROUND 5-10 KT BETWEEN 125W-135W.

$$
MUNDELL